It can be appreciated that valve actuator assemblies have been in use for years. These assemblies control the flow of liquids or gasses in a variety of industrial and mechanical settings. Typically, valve actuator assemblies comprises one of three main types of design: those comprising diaphragm actuators, actuator pistons, or electromechanical actuators. These assemblies are typically used in controlling one or more functions of internal combustion engines or in other industrial applications.
The main drawback with conventional valve actuator assemblies is that the valve typically needs to be biased closed with an extremely high spring pre-load in order to counter-act or negate the force created by the working pressure of fluid (or gas) against the face of the valve. Another problem with conventional valve actuator assemblies is that the high spring pre-load requirement reduces the responsiveness of the actuator to control the valve. Another problem with conventional valve actuator assemblies is that they are typically over-designed to be far more robust than they would otherwise need to be in order to withstand the high spring pressures mentioned heretofore.
While the valve actuator assemblies just described may be suitable for the particular purpose to which they address, it would be desirable to reduce the high spring pressures in order to reduce the design requirements of the valve and actuator and improve responsiveness.